Method for introducing an active compound into a soft hydrated contact lens

Abstract

A method for introducing an active compound into a soft hydrated contact lens comprising the steps of: providing a hypotonic aqueous solution having an osmolarity value less than 150 mOsm and an effective quantity of that active compound, immersing the soft contact lens in the aqueous hypotonic solution, subjecting the contact lens immersed in the aqueous hypotonic solution to mechanical vibrations having a power greater than 100 mW for a predetermined time.

Claims

1. A method for introducing a lubricating agent into a soft hydrated contact lens, the method comprising: providing a hypotonic aqueous solution having an osmolarity value less than 150 mOsm and comprising an effective quantity of the lubricating agent to be introduced into the contact lens, immersing the soft contact lens in the aqueous hypotonic solution, subjecting the contact lens immersed in the aqueous hypotonic solution to mechanical vibrations having a power greater than 100 mW for a predetermined time, wherein the predetermined time during which the contact lens, immersed in the aqueous hypotonic solution, is subjected to mechanical vibrations, is at least 10 seconds, divided into cycles of 2 to 10 seconds every 10 to 25 minutes.

2. The method according to claim 1, wherein the lubricating agent is introduced between applications of the soft contact lens to an eye of a user.

3. The method according to claim 1, wherein the aqueous hypotonic solution further comprises a disinfecting agent in order to disinfect the soft contact lens when it is immersed therein.

4. The method according to claim 1, wherein the mechanical vibrations have a frequency of at least 100 Hz.

5. The method according to claim 1, wherein the aqueous hypotonic solution has an osmolarity of from 100 mOsm to 130 mOsm.

6. The method according to claim 1, wherein the aqueous hypotonic solution comprises a fraction by weight of NaCl of from 0.2% to 0.4%.

7. The method according to claim 1, wherein the lubricating agent is selected from the group consisting of: hyaluronic acid, a salt thereof, galactoxyloglucan extracted from tamarind seeds and an admixture thereof.

8. The method according to claim 7, wherein (1) the lubricating agent is the admixture of (i) hyaluronic acid or a salt thereof and (ii) the galactoxyloglucan extracted from tamarind seeds, and (2) the hyaluronic acid or salt thereof is present at a fraction by weight of less than 0.05% of the hypotonic aqueous solution.

9. The method according to claim 8, wherein the hyaluronic acid or a salt thereof is present in the aqueous hypotonic solution at a fraction by weight of from 0.01% to 0.035% and the galactoxyloglucan extracted from tamarind seeds is present in the aqueous hypotonic solution at a fraction by weight of from 0.005% to 0.035%.

10. The method according to claim 1, wherein the soft hydrated contact lens comprises a hydrogel based on hydroxyethyl methacrylate or based on silicone.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The features and advantages of the invention will be better appreciated from the detailed description of a preferred embodiment thereof which is illustrated by way of non-limiting example with reference to the single appended drawing, in which FIG. 1 is a schematic perspective view of a device for containing a contact lens which is provided for operating in accordance with the method of the present invention.

PREFERRED EMBODIMENT OF THE INVENTION

(2) In the appended single FIGURE, there is generally designated 1 a device for containing a contact lens which is provided to operate in accordance with the method for introducing an active compound into a contact lens of the present invention.

(3) The device 1 comprises a pair of receptacles 2, for example of cup-like form, each receptacle 2 being provided to contain a contact lens which is immersed in a preserving solution and being able to be closed with a cap 3.

(4) The device 1 further comprises a vibrating member 4 which is associated with the pair of receptacles 2 in order to subject the receptacles and the content thereof to mechanical vibrations.

(5) More specifically, the vibrating member 4 may be of the type having an eccentric mass which is caused to rotate about an axis thereof at a predefined rate by an electric motor 5 which is supplied, for example, by a battery 6.

(6) The activation and deactivation of the electric motor 5 is controlled by a control unit 7 which is inside the device 1, preferably of the programmable type, which can be activated by the user by means of buttons 8.

(7) A display 9 which is connected to the control unit 7 communicates to the user information concerning the operating state of the device 1.

(8) In the preferred version described here, the electric motor 5 has a maximum input power of approximately 300 mW and actuates the vibrating member 4 in such a manner as to generate mechanical vibrations at a frequency between 150 and 250 Hz, preferably approximately 200 Hz.

(9) The control unit 7 may be programmed in order to carry out a cycle of vibrations for a predetermined time or, in a greatly preferred manner, to carry out successive cycles of generation of vibrations alternating with rest periods.

(10) The device 1 is advantageously used as a container for placing the soft contact lenses at the end of the day (or the period of application to the eye) in a state immersed in a preserving solution having the characteristics set out above in the general description of the invention.

(11) A preferred example of preserving solution, in which the soft contact lens is immersed, is a solution of distilled water in which the following components are dissolved:

(12) hyaluronic acid (MW of approximately 800 KDa): 0.015%

(13) TSP (MW of approximately 800 KDa): 0.015%

(14) boric acid: 0.43%

(15) disodium tetraborate: 0.085%

(16) sodium chloride: 0.3%

(17) EDTA: 0.1%

(18) polyquaternium-2: 0.001%

(19) viscosity promoters: 1%

(20) polyhexamethylene biguanide solution: 0.0005%

(21) The solution has an osmolarity value of approximately 125 mOsm.

(22) Once the control unit 7 has been activated by means of the buttons 8, the vibrating member 4 is actuated by the motor 5 for a first period of time of approximately 15 seconds, after which it begins a series of cycles of switching on and off in which the switching off period lasts approximately 15 minutes and the switching on period lasts approximately 5 seconds, which continue in succession in such a manner that the total period of actuation of the vibrating member 4 is approximately 2 minutes.

(23) The soft contact lens immersed in the preserving solution absorbs a given quantity of solution which is estimated at approximately 20 microliters, while the action of the mechanical vibrations, breaking up any agglomerations of active compound and/or causing the dynamic recirculation of the water bonded to the hydrogel internally with respect to the contact lens, also promotes the introduction of the active compound therein so as to obtain a substantial equilibrium between the concentration of active compound in the liquid component inside the contact lens and in the preserving solution outside it.

(24) The soft contact lens taken from the receptacle 2 at the end of the processing operation has therefore incorporated in its own liquid component a significant quantity of active compound and may be applied to the eye of the user again.

(25) The present invention therefore solves the problem set out above with reference to the cited prior art.